The present invention relates to tire condition sensing and, more particularly, to an apparatus and method for tracking the duration of an abnormal tire condition in a tire condition sensing system.
Numerous tire pressure monitoring systems have been developed in order to detect when the air pressure within a tire drops below a threshold pressure value. A system typically includes a pressure switch, an internal power source, and a communications link. The pressure switch provides tire pressure information to a central receiver through the communications link. The communications link may be a wired or wireless link.
There has been an increasing need for tire pressure monitoring systems due to the use of xe2x80x9crun flatxe2x80x9d tires in vehicles. xe2x80x9cRun flatxe2x80x9d tires enable a driver to travel an extended distance after a substantial loss of air pressure within a vehicle tire.
Examples of tire condition monitoring systems which maintain information related to a detected tire condition are disclosed in U.S. Pat. Nos. 5,825,286, 5,754,965, 5,559,484, 5,731,754, 5,581,464, and 4,186,377.
One aspect of the present invention provides an apparatus for tracking an abnormal condition of a vehicle tire. The apparatus includes a receiver that receives a data message having data indicative of a condition of the vehicle tire. A controller is connected to the receiver and is responsive to the data message received by the receiver. The controller includes a counter that has a value indicative of a duration of an abnormal tire condition. The controller adjusts the counter value as a function of the content of the received data message.
Another aspect of the present invention provides an apparatus for tracking an abnormal condition of a vehicle tire. The apparatus includes a receiver for receiving a data message that includes data indicative of an operating mode of a transmitter module associated with the vehicle tire. The data message also includes data indicative of a condition of the associated vehicle tire. A controller is coupled to the receiver for determining an operating mode of the transmitter module based on the data message. The controller includes a counter having a value indicative of a duration of an abnormal condition for the associated vehicle tire. The controller, in response to receiving a data message indicating the abnormal tire condition, adjusts the counter value based on the operating mode data of the data message.
Still another aspect of the present invention provides a system for tracking an abnormal condition of a vehicle tire. The system includes a transmitter module having a tire condition sensor for sensing a condition of the associated vehicle tire and a transmitter for transmitting a data message having a characteristic indicative of the sensed condition. A receiver remote from the transmitter module receives the data message. A controller is connected to the receiver and responsive to the data message received by the receiver. The controller includes a counter having a value indicative of a duration of an abnormal tire condition. The controller adjusts the counter value as a function of the content of the data message.
Yet another aspect of the present invention provides a method for tracking an abnormal tire condition in a tire condition monitoring system. The method includes receiving a signal having a data message indicative of a condition of an associated vehicle tire. The method further includes the step of counting values indicative of a duration of an abnormal tire condition of the associated vehicle tire and adjusting the count value as a function of the content of the received data message.